* Wei Wang (wei.w.w...@intel.com) wrote:
> Count the number of 1s in a bitmap starting from an offset.
>
> Signed-off-by: Wei Wang <wei.w.w...@intel.com>
> CC: Dr. David Alan Gilbert <dgilb...@redhat.com>
> CC: Juan Quintela <quint...@redhat.com>
> CC: Michael S. Tsirkin <m...@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> include/qemu/bitmap.h | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h
> index 509eedd..e3f31f1 100644
> --- a/include/qemu/bitmap.h
> +++ b/include/qemu/bitmap.h
> @@ -228,6 +228,19 @@ static inline long bitmap_count_one(const unsigned long
> *bitmap, long nbits)
> }
> }
>
> +static inline long bitmap_count_one_with_offset(const unsigned long *bitmap,
> + long offset, long nbits)
> +{
> + long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG);
> + long redundant_bits = offset - aligned_offset;
> + long bits_to_count = nbits + redundant_bits;
> + const unsigned long *bitmap_start = bitmap +
> + aligned_offset / BITS_PER_LONG;
> +
> + return bitmap_count_one(bitmap_start, bits_to_count) -
> + bitmap_count_one(bitmap_start, redundant_bits);
> +}
> +
> void bitmap_set(unsigned long *map, long i, long len);
> void bitmap_set_atomic(unsigned long *map, long i, long len);
> void bitmap_clear(unsigned long *map, long start, long nr);
> --
> 1.8.3.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
